Printing machine



June 5, 1928.

A. B. EVANS PRINTING MACHINE Filed Dec. 17, 1927 '7 Sheets-Sheet 1 Fig.1.

Inventor .4 B. E mno ifl I V Attorney.

June 5, 1928.

A. B. EVANS PRINTING MACHINE Filed Dec. 17,1927

Fig.1?

7 Sheets-Sheet 2 Inventor 14.3. Evmw y k 2 W:

Jttorney.

June 5,1928.

A. B. EVANS PRINTING MACHINE 9 Filed Dec. 17, 1927 '7 Sheets-Sheet 3 8 7 t t A ial- Inventor ABEW Attorney.

June 5, 1928.

A. B. EVANS PRINTING MACHINE Filed Dec. 17, 192'! Sheets-Sheet 4 I I I I I I I I I I I June 5, 1928.

A. B. EVANS PRINTING MACHINE Filed Dec. 17, 1927 I 7 Sheets-Sheet 5 lllll Inventor fl. B. EI/rnm M i, W.

, Attorney.

7 Sheets-Sheet 6 "A. B. EVANS PRINTING MACHINE Filed- Dec. 17, 1927 June 5, 1928.

Inventor fl .B. E mmo llttorney.

June 5, 1928. 1,672,715

A. B. EVANS PRINTING MACHINE Filed Dec. 17, 1927 '7 Sheets-Sheet 7 Inventor y W. 2. M.

- presented by them'tothe machine,

Patented June 5, 1928. I

unit an STATE ART-HUB BUBBOU'GH-ES EVANS, 1 on LEEDS, ENGLAND.

PRINTING MACHINE:

Application flled necember 17, as,

This invention relates toprintingmachines and especially to machines-such as are used for printing on tin plates-or sheets. In machines used for printing; on tin plates or sheets, it has been'usual'for one operator tofeed the platesor sheets'by hand" to the machine, either directly or by means of a semi-automatic apparatu-sby I whichth'e' plate or sheet is fed by hand into a registering apparatus which conducts the plate or sheet to the'pr-inting part 'of the machine Such amechanism has the disadvantage that the maximum speed attainable by the machine is. determined by the capacity ofa' single operator in handling the'tin plates orsheets, and the invention has among its objects" to avoid this disadvantage.

The object offthe invention is to enable twooperators alternately to feed the tin plates or sheets to the machine respectively on alternate cycles oroperations of the machineunder conditions whereby overlap ping of the actions of'thetw'o operators, or of: the movements of" the plates or sheets may be prevented.

According tothe invention means are provided for arresting the-sheet at the feed board such as described in the specification of the prior Patent No. 1,433,991, and in addition, one back lay and t wo side'lays are provided having movements fOr registering the sheet at the front lays of the machine, as well as a detector motion by which the machine is tripped in the absence of a sheet, or alternatively in" the case of a sheet being out of register on the feed hoardatthe time itshould be" in register, for the reason, for 7 example, that thesheet is too narrow, and, in addition, means areprovided whereby the printing position will auto matically be recovered in the machine on a sheet being correctly presented on the feed board; i

According to the invention, moreover, means such as preliminary front lays, slightly in advance ofthe' front lays of the machine, are provided to prevent any sheet from entering the machine before-the front lays are in their laying-on position;

' By such means the alternate action of the two o erator-s maybe' determined, and two operators are enabledto teed sheets-to one and the same machine" which is running at double the usual" speed; H

The: accompanyingdiagrammatic drawthe slot.

Serial 110. 249,854, and in Great'Britain June :16, 1926.

ings illustrate, byyvvay of example; a "construct'ion' of" printing machine adapted for printing on tin" plates or sheets and provided with the mechanism in accordance with theinvention.

Figures l and 1 togethercomprise a" side elevation .of the machine.- I

togethercomp'rise a plan Figures- 2 and '2' the impression cylinview' of themaehi-ne, der being removedi 'Figurec?) is a sectional elevation of the machine taken upon't'lie line 3+3*ofFigures 2and2;

, Figure l is a cross-section oftlie-machine taken ongthe" line 44 of Figures 2' and 2.

Figure 5 is a detail cross-section illustratmg the connection of themechanism" accord ingto the invention'with" the tripping gear of the machine; V

Figures 6,17 and '8: are respectively side elevation, end elevation and plan of one of therside' lays'orback" lays. i

In carrying the invention intoeflect in 1 accordance with the construction illustrated inthe accompanying drawings, the feed pla te I a is provided with transverse slots 6 anda longitudinal slot 0' to serve as guides for the side lays (t and the back lay e respeca tively. Each lay is providedwith a runner al 6 (Figures 6and 8) respectively: mounted upon the body of. the-la. in such manner as to be capable of limited movement in the direction of the length ofthe correspond? ing slot'b, 0 respectively in the mannerheree. ,inafter fully describedl Such movement is efiected against springpressure and th'e construction offthe lays is such that the respecg tive runners may be fixedly" secured with reference to the corresponding lay" body; The sidelays cf are respectively mountedupon bars f disposed below the corresponding slotsb of the feed plate and mounted in bearings provided upon the underside of the feed plate so as to be "capable of a re.- ciprocatory movement. Similarly the back layis' mounted upon a bar gdisposed below the slot 0; and adaptedfor a reciprocatory movement in t-he'directio'n of the length of The mechanism for efi ecting the necessary reciprocation of the side-and back lays comprises a se entallever It secured toa pivot pin it ignre 44) disposed in a position normal'to theunderfaceof the feed plate a and having secured toit'an' h operated by suitable cam" mechanism from. any

convenient'part' of the mechanism of the printing machine; for example, as illustrated, the arm 7L. is oscillated by a connecting rod 713, connected to a swivel head on the arm, the far end of the rod being pivoted to the free end of a lever 71, fulcrumed at the side of the machine frame and carrying a runner or roller to engage a cam it mounted upon theshaft 2 of the printing cylinder 2. The segmental lever .72, is formed at the periphery with teeth adapted to engage a rack j provided on a rack bar mounted in bearings under the feed plate to permit longitudinal reciprocation and having rack teeth for engagement with a pinion k mounted upon. a spindle carrying a pinion (Z for engagement with a series of rack teeth formed on the adjacent bar 7. The pinion is also engages with a pinion Z which serves to effect reciprocation of the bar g by engagement with ascries of rack teeth provided upon the adjacent lateral face of the bar. The opposite face of thebar is similarly provided with rack teeth for engagement with a. pinion Z ,.whieh in turn engages a pinion 74 mounted upon a spindle carrying a pinion (Z adapted to engage with rack teeth formed upon the second of the bars 7. By such means it will beobserved that upon the angular reeiprocationof the segmental lever 7b, the bars 7' and g willbe reciprocated to effect the movement of the side and back laysv 03 and 6 respectively be tween the positions indicatedin Figures 2 and 2 in full and dotted lines. Thus, if a sheet of tin or the like is placed upon the feed plate a during the time that the side lays (Z and the back lay a are at thev outer limits of their travel, upon the return of the lays to their inner limits of travel the sheet will be registered against the front lays m of the machine by. the action of the back lay cand one of the side lays d, the second side lay (Z being set so that the runner al may have the relative movement with respect to the body of the lay hereinbefore referred to, .and thus set itself according to the position of the edge of the sheet of tin or the like.

The front lays m are mounted adjustably upon a shaft m carried by the framework of the machine advantageously in movable bearings in such manner that the position of the shaft maybe adjusted. The shaft has fixed upon it an arm m? and is mounted under spring action tending to throw the lays m into the upper position. A shaft 22 is j ournalled in hearings in the machine framework and serves to carry by means of arms 2? two rotatably mounted shafts s, s serving respectively to support the elements of a number of sets of grippers. Thus, the. inner shaft 8 carries a series of arms s substantially radially disposed with respect to the shaft z and forming, by means of their heads,

the lower grippersurfaces, whilethe upper shaft 8 serves to carry a corresponding ment of oscillation in the manner hereinafter described. The upper arm i serves to carry;

a pin wa adapted to engage with the arm m for the depression of the lays m. Also r0 tatably mounted upon the shaft 6 adjacent the said fitting F, t, t and adjustably secured to the arm t bysuch means as an adjustable pin and slot connection, there is provided a cam plate formed with two cam sur-,

faces 8 a, one of which 8 acting as a bear-' ingsurface is adapted to engage with a runner s mounted upon an arm secured to. the shaft sand the other of which, 8 is adapted to engage with a runner a carried by an arm secured to the-shaft 8 so thataccording to the positionof the fitting t 25 and when thesets of grippers are in the receiving position, the gripper fingers s areraised to admit; a sheet from the-front lays m orare lowered'to engage the sheet.

To effect the oscillatorymovement of the grippers necessary for the feeding of the sheets to the impression cylinder 2, the shaft 27 is extended from the framework on the one side for the reception of a chain pulley "/5 Sit around which is wrapped and secured a chain 6 Connectedhy a connecting rod to a swivel fitting mounted at the lower end of a lever i fulcrumed upon the machine frame and carrying a runner adapted to engage a cam mounted upon the adjacent extremity of the impression cylinder shaft The return movement of the chain pulley Z,

and thus of the grippers to the receiving position, 1SQfiGClZCCl by the action of a con pression spring 15' disposed in a vertical position and anchored at the lower end to the machine frame and atthe upper end to the chain pulley tby means of pivoted telescopic rods or plungers, advantageously screw-threaded for the reception of nuts whereby the compression of thespring 6 maybe varied. I

In order that the grippers may be opened to release the sheet in the position .in which the impression cylinder 2} receives it, the shaft s is also provided with an arm carrying a runner s for engagement with a cam plate 3 secured adjustably in positionupon the machine frame by means of bolts. The carries apin r tem-2,7 1 5 w spring 6" tending always to rotate the lite ting upon the shaft r in an anti-clockwise direction. This movement is limited, howevergby means 'of a lug t upon the fitting which is adapted tocont'act with an adjustable pin stop mounted upon the machine frame. u is a fulcrum shaft extending across the machine frame and upon which is mounted a trip pedaltof. An arma is also mounted upon the shaft to and is connected to a rod u? extending upwardly and" passing loosely through a swivel fitting o v of the claw lever 27, which is pivoted to a leverw tulcrumed upon the machine frame at w and carries a runner for engagement with a cam 10 mounted upon the adjacent end of the plate cylinders or plate cylinder shaft .2 The cam thus rotates oncein every cycle of the machine. A compression spring a is mounted uponthe rod a between the swivel fitting-o and an adjustable collar upon the rod 10"".

The claw lever v engaged from the pin t according as; the trip pedal 14* israi'se'd or lowered at the appropriate time for engagement or disengagement, that is to say, when the lug t is engaging thest'op t The detector mechanism, by which the machine is tripped in the absence of a sheet or in the case where t-hesheet does not properly registeragainst the front. lays m, cornprises a rod n mounted below the feed plate a in a position" adjacent to, and parallel with, the bar 9 and in bearings such as to permit longitudinal movement thereof. A spring 91/ coiled around the rod between one ofthe bearings and a collar up'on-the'rod serves to presstlie roda'in the direction towards the rear of the plate (1 where the rod is adapted to engage an arm 11 upon'a transverse rod n carried in bearingsfixed to the feed plate andhaving also an arm n whiohis connected through a connectingrod 12- with the tripping mechanism otthe printing machine. A bracket or arm 6 connected to the runner e of the back lay e'is' provided to embrace the rod w and to contact, on the forward movement of the back lay, with an adjustable collar a mounted upon the rod ffb so' that the rod 12 is moved longitudinally and "the tripping mechanism operated through the rod 11 It will be understood that when a sheet of tin is in position and has been pushed into register with the front lays'm by the back lay a the runner 6 is moved rearwardly relatively'tothe body of the lay and the bracket or arm e fails to contact withthe collar a, so that notripping Y of the machine takes place. WVhen' no'sheet is present on the feed plate, however, or when the sheet fails to reach the front lays, for the reason, for example, that it is too narrow, the relative movement ofthe runner 6 with respect to the bodyof tlie lay does is engaged with or disnot take plaeeso' that'the bracket or arm 0 contacts with: the collar n and carries the rod 'rv forward-whe eby the tripping mechanism becomes operative;

The connection between the detector mechanism of the feed mechanism and the trip gearot' the machineis advantageously. rovide'd according to the construction il ustrated in the drawings. The rod 71, is connected also to a bell crank lever 11 pivoted on the frameworkof the machine'and carryinga depending member p adapted always toengageby contactat one side with the lower arm of a bell crank lever '9 also pivoted on the framework and carrying a runner 9' operated by a cam g on the shaft a; The lower arm of the lever g iscurved or diverted to enga'gethe depending member p which is thus caused to swing at the re-i quired moment once in each cycle.

The depending member p can alsoengage,

iss principle, one mm W of a three-armed l'ever 1' also pivo d o the framework and co e a rod r to'rnechan'ism co-operating with the trip mechanism of the machine, The' threearmed lever 1' is mounted that it is returned. to its initialposition, resting on a stop 7", by a spririg'r"; Y i p I The operation of the'rod' a for tripping thus causesthe member p to be lowered so that whenitswin'gs under the action of the bell crank lever 9 it engages and throws over the three-armed lever 1" which etlects movement otthe rod 1'?" as may be required,

giving the effect that the trip pedal a of the machine is held a in, the tripping position and the machine is tripped.

I For the'connection of this-mechanism with the trip mechanism there is provided at the foot of the frame a bracket 0" having two bosses or bearings r 7" mutually at right anglesand serving respectively as bearings for a sp ndle v to which 15 secured at one end an arm r connecte'd" with the rod 9' by a conn'ection which is adjustable, and at the other end an' armythe extremity of which is disposed on the axis of the boss or bearing 7'. The latter serves to receive a slidably mounted pin 1" mounted under spring action tending to throw it outwards towards the said arm rm'and'having the forward end undercut or formed as an inclined or catch face: The said bracket 1 is disposed immediately adjacent the trip pedal 10* of the machine, which pedal is provided with a pivoted angular member to comprising two arms, one of which lies below the arm of the pedal andis adapted to engage an adjusting screw at, by which the position of the m'enr her may be adjusted, and the other-arm M7 of which isprovided with a hook of a shape to correspond to the forward end of the pin 1* and is sodisposed that in the movement of the pedal the hook passes betoo low the pin r. The member U5 is maintained in its position of adjustment against the screw it bymeans of a spring a connected between the pedal arm and the arm a of the member if. The pedal a is mounted upon the shaft a and is provided with an arm a connected b a connectin 3 b a connectin rod m with a bell-crank lever 00, the free arm of which is adapted to contact with the stop M13 on the connecting rod 10 The connecting rod m 1s mounted under the action of a spring w tending to maintain the runner against the cam a; and the bell-crank lever away from the stop it.

. The preliminary or auxiliary front lays 0 are positioned a short distance to the rear of the front lays m and are carried by levers 0 carried by a spindle '0 which is rocked or oscillated through the arm 0 by a rod 0 and a lever 0 fulcrumed upon the machine frame and having a runner for operation by an adjustable cam 0 on the shaft 2 of the cylinder 2. The lays 0 are adapted to project above the feed plate a immediately a sheet is passed, and to fallbelow the feed plate as the front lays m are moved into position to receive the succeeding sheet, the timing of this operation being effected by correct adjustment of the operating camf An advantageous construction of the side and back lays is illustrated in Figures 6, 7 and 8. .The body of the lay (Z is provided of channel shape and is supported upon the bar f by a channel shaped bracket (Z which is clamped to the bar by means of a plate bolted to the bracket. One side of'the bracket (Z is provided of slightly less depth than the other so that by means of an adjusting bolt d the plate 01 may be drawn tightly against the bar f to determine the position of the lay. A clamp (Z constructed similarly to the bracket (Z is mounted upon thebar f forward of the bracket 0? and the two are connected to gether by means of a screwed pin (i which ing nut al secured upon the screwed pin volved about the shaft t for the forward feed The runner (Z is rotatably. mounted therein by means of a stop plate 0? and an end plate 05 The runner is maintained in the forward position with reference to the body'cl by means of a helical spring cl disposed within a bored recess in the plunger cl. In order that the pressure of the spring may be adjusted, the

end plate (Z carries a screwed pin 03 hav ing a collar (Z against which the spring bears, so that by adjustment of the pin (Z in the end plate, the position of the collar (Z may be varied. Thebody (Z is closed by a cover plate (Z upon which is mounted the head or shielded which is of oblong, elliptical or oval shape. When it is desired that the plunger (Z should'be secured within the body of the lay 03 so that the runner (Z and the body dare not relatively movable, the screwed pin (Z is screwed home toenga-ge the plunger in the position in which it is desired to be adjusted within the body 01.

In the operation of the machine, during a complete cycle, a tin plate or sheet placed upon the feed plate win proximity to'the preliminary lays 0 is-first fed forward into register with the front lays-m bythe side lays (Z and the back lay a. The movements of the side and back lays are effected by the ated from the cam if, and onthe forward are lowered from the operative position by the mechanism as hereinbefore described op-v erated from the cam 0 By the time the plate or sheet has arrived in register with the front lays m, the three armed fitting .6 t i will have been moved by the claw lever '0 under the action of the cam 10 into the position where the lug 25 contacts with the pin stop 15 In this position the cam sur-, face 8 will have engaged the runner s in such manner as to open the gripper fingers s and the pin m will have moved toa position in which it has permitted the .arm m to rise to bring the front lays m into the operative position. j In the continuationof the cycle of opera-v tions, the three-armed fitting 6 25 23*, is partially rotated by the claw lever oto move the cam surface s away from the runner s movement of the plate or sheet under the 1 .action of the back lay "e, the preliminary lays and to cause the pin m to depress the arm m Thus the gripper fingers s are permitted to fall to engage the plate or sheet upon the arms 8, and simultaneously the front lays m are depressed. The. chain wheel i is now partially rotated by the action of the lever 25 and the cam .2 with the result that the shafts s and sare re tinued operationiof the machine, the shafts,

' tripping of the meohanlsm of the machineis gages the collar effected in the usual way and thecam w, the

arms 00 w, the connecting rod 03 and thebell crank lever 00 .act upon the stop a -.to effect a depression of the trip pedal a1 and thus the disengagement of theclaw ilever o from the pin i at the correct time. At the same time the cam g acting upon the runner g serves-to oscillate the arm 9, but inasmuch as the detector-mechanism has not been'operated, the three-armed lever r is not-engaged; by the depending member 19 When,lhow

ever, there is a failure to feed (a plate or sheet to the feed tableor it is fed in such away that it is improperly engaged by the side and-back laysso that it'failsto engage with the front lays on on the forward movement of the back lay e, the runnere of the said lay is not moved relatively to the lay body e andaccording'ly the bracket 6 on 01- upon the rod n in the manner hereinbefore described. In thesecircumstances the depending member 11 isde' pressed to the extent that upon the next oscillation of the lever .g the .lever -1 is rotated upon its pivot to throw forwardithe pin r so that this engages with the hook of the arm a on the trip pedal .utand maintains this in the tripping ;position.* When the :trip pedal w is depressed :and held adepressedthe'claw lever o is disengagedfrom the three-armed fitting 125 t t -so that this remains inthe.position with-thelug restingagainst the step t and thus thegripper fingers s will fail to close and the .front lays m will not be withdrawn from theoperative position is caused torelease the trip pedal u, by the action of its spring upon the next depres sion of the trip pedaliby-the cam an t The mechanism hereinbefore d .ribed permits (two operators to be employedon a single machine, each operator feeding sheets independentlyand alternately with his. fellow :to alternate cycles or .operations of the machine, rsince each sheet correctly :fed by the Ifirst operator is taken from the front lays by the feed grippers ofthe machine, and each sheet incorrectly fed'bythe first'opere ator remains on the feedvplate .in full view of the second operator who therefore will refrain from: feeding the machine :till. :the sheet in question has either been registered orremoved; further, when thelfirst operator omits to feed a sheet :the :second aOPOHRtQI, finding no. interference, will continue feeding according :to this proper machine will automaticallyi-be tr pped for each of the omitted sheets and returned to ,Inthe meantimethe until such time as ithe ,pinm

' connecting hereinbefore .described.

cycleand the the printing position inaccordance with the action described.

It will beunderstood that the invention is not limited to the particular details'of construction of the parts of the mechanism as hereinbefore described.

It will be understood that the side lays maybe replaced by registering stops which may be of fixed position when the machine is used to operate upon plates orlsheets of standard or determined dimensions.

I-claim:

il.-'Printing machines and especiallymas,

chines for the printing. of tin plates and board and the impression cylinder, means operated from the mechanism of the machine ,for efiecting .the withdrawal of the front ilays and the operation vof the feed Grippers, tripping mechanism applied to the.

ront lays and the-feed grippers,la detector element mounted upon the feedfhoarfd for operationiby the :back lay thereon, and mechanism connecting the said detector element with the'tripping me.chanisni, substantially as .hereinbefore described. j v

.2; .Printingv machines and vespecially ma chinesffo'r: the ,printing of tin plates or sheets, comprising a feed board, slots in said acting upon the back feed boar-don lines disposedat right angles,

back and side .lays mounted to. move. in said slots, reciprocatory bars mounted below said I feed. \board in line porting said back Eand' side lays, means for reciprocating said' fbars operating fromfla' rotatable element of the. machine, front lays positioned in advance 7 of the feed :board, feed}grippers mounted between .the feed board and the impression cylinder, means operated fromthemechanism ofIthe machine for .e'fif'ecting the withdrawal or the front lays and theoperation'of the feed grippers, trippingmechanism appliedto the front lays and the feed ,grippers, a detector element mounted \upon the feed board for operation by the back laythereon', vand mechanism the said detector, element with the tripping anechanism, substantially as 3. Printing 1naclnes and especially machines for the printing of tin plates :or' board, slots in sheets, comprising a feed said -.feed board, back and side lays disposed ,respectivelyfin said slots, reciprocatory bars .upon which said back-and, side lays rare mounted, rack teeth upon. said bars,

with'said slots and sup-,

teothggear -engaging said rack teeth and gearing said bars together, a reciprocating driving rack bar engaging and driving said in advance of the feed board, feed grippers mounted between the feed board and the impression cylinder, means operated from the mechanism of the machine for effecting the withdrawal of the front lays and the operation of the feed grippers, tripping mechanism applied to the front lays and the feed grippers, a detector element mountsheets,

ed upon the feed'board for operation by the back lay thereon, and mechanism connecting the said detector element with the tripping mechanism, substantially as hereinbefore described. p

4. In printing machines and especially machines for the printing of tin plates or sheets, comprising tripping mechanism, a back lay adapted to reciprocate upon the feed board, means for operating said back lay, a detector member upon the said" back lay relatively movable thereto, a movable control member lying adjacent the path of the back lay to contact with the detector member, a rotatable member driven from the mechanism of the machine, an oscillatory member oscillated by the said rotatable memher, and a trip'mechanism detaining member, mechanism for operating the said detaining member, the control member engaging said mechanism with the oscillatory member, substantially as hereinbefore described.

5. In printing machines, and especially machines for the printing of tin plates or comprising tripping mechanism, a gripper and front lay operating member, a reciprocating member engaging the said lay operating member, a rotatable member receiving movement from a rotary element of the machine and imparting motion-to the reciprocating member, a tripping member engaging with the reciprocating member, a trip operating member connected with and serving to actuate the tripping member, a second rotatable member receiving movement from a rotary element of the machine, an oscillatory member engaging with and operated by the said second rotatable member, and a member connected with the said second oscillatory member and adapted to engage the trip operating member, hereinbefore described.

6. In printing machines, and especially machines for the printing of tin plates and sheets, provided with tripping mechanism, a feed board, a back lay movable upon said feed board, a detector member carried by said back lay, a control member disposed adjacent the path of the back lay and for substantially as engagement with the detector member, a

cam rotated from the machine mechanism, a lever oscillated by the said cam, a second lever disposed adjacent to but not engaging the first lever, a movable intermediate member connected with and moved by the control member and in one position engaging the two levers, and a tripping mechanism de taining member connected to and operated by the second lever, substantially as hereinbefore described. I

7. Printingmachines and especially machines for the printing of tin plates and sheets, comprising a feed'board, back and side lays movably mounted upon said feed board, means operating from'the mechanism of the machine and acting upon the back and side lays to effect their reciprocation relatively to the feed board, movable front lays posltioned in advance of the feed board,

preliminary front lay'sdisposed between the back lay and the front lays, means operated from the mechanism of the machineefl'ecting the movement ofthe preliminary front lays, substantially as hereinbefore described.

Ell

8. Printing machines and especially machines'for the printing of tin plates and sheets, comprising a feed board, back and side lays movably mounted upon said feed board, means operating from the mechanism of the machine and acting upon the back and side lays to effect their reciprocation relatively tothe feed board, movable front lays positioned in advance of the feed board, preliminary front lays positioned in openings in the feed board, a transversely disposed shaft rotatably carried by the machine,

preliminary front "lays i the sald shaft, an operating described.

9.Printing machines and especially machines for the printing of tin plates and sheets, comprising a feed board, back and side lays movably mounted'upon' said feed board, means operating from the mechanism of the machine and acting upon the back and side lays to effect their reciprocation relatively to the feed board, movable front lays positioned in advance of the feed board, a transverse shaft rotatably; carried by the machine, feed grippers supported from-the said shaft, an operating wheel secured to the said shaft, a cam adapted to be rotated from a rotary element of the machine, a lever adjacent to and oscillated by the said cam, a flexible member secured to the said wheel and connected to the said lever, a spring connected to the said wheel, an anchorage for the said spring provided upon the machine frame, the said spring opposing the action of the lever, an oscillatory member mounted upon the said shaft and operating the feed grippers and the front lays, trip-' pmg mechanism applied to said oscillatory member, a detector elementv mounted upon the feed board for operation by the back lay thereof, and mechanism connecting the said detector element With the tripping mechanism, substantially as hereinbefore described.

10. Sheet feeding mechanism forprinting machines and especially for machines for the printing of tin plates and sheets, com prising in combination a feed board, means on the said feed board for registering a sheet thereon, means forfeeding the said.

sheet from the said feed board to the'grippers of the impression cylinder of the printing machine, a detector element cooperating with the said means for registering a sheet to detect the absence of a sheet and the improper placing of a sheet upon the feed board, and tripping mechanism Ioperated by the detector element to prevent'the operation of the said means for feeding sheets to the grippers of the impression cylinder of the printing machine, substantially as hereinbefore described.

11. Sheet feeding mechanism for printing machines and especially for machines for the printing of tin plates and sheets, comprising in combination a feed board, a back lay on the said feed board, means operating from the mechanism of the printing machine to effect the reciprocation of the said back lay to bring the sheetinto register, movable frontlays, sheet transfer mechanism adapted to carry a sheet from the feed board to the grippers of the impression cylinder of the printing machine, and de-,

lay on the said feed board, means operating from the mechanism of the printing machine to effectthe reciprocation of the said back lay to bring a sheet into register, movable front lays, mechanism operated from the mechanism of theprinting machine to prevent thetransfer of the sheet from the feedboard to the grippers of the impression I cylinder when said sheet is not in register,

substantially as hereinbeforedescribed.

ARTHUR BURROUGHES EVANS. 

